The science fails in this movie are just ridiculous. Maybe this movie would make sense in some alternate universe with different laws of physics, but it doesn't make any sense in this universe. I won't go into all the fails, there's too many of them, but the biggest one is the whole premise. If a supernova close enough to be a problem were really to go off, then at our current level of technology we would be totally fucked. They're trying to use nukes to shield the Earth from the supernova blast. But as kengr pointed out, if it really happened, the supernova blast would be a problem for 20 or 30 years. Even if that weren't true, I still doubt nukes would be much help.
The worst part of the movie is the Russian guy. Whoever is playing him is the worst actor I've ever seen. His voice is really weird, his accent is bizarre. You should watch this movie just to see how bad it is.
Seriously, its only redeeming quality is it has Brian Krause from Charmed on it. He is the only decent actor in the whole movie. Somehow, his presence makes the premise seem a little more plausible. I suspect this is why they chose him.